The use of high pressure drilling fluid in conjunction with earth boring drill bits is well known in the field of well hole drilling. Drilling fluid nozzles generally are provided at the drill bit for directing fluid to clean and cool the cutting elements and to flush the formation cuttings toward the surface. Various drilling fluid flow paths are utilized depending, to some extent, on the composition of the earth formation being drilled. Most drill bits include downwardly directed nozzles for flushing and removing the formation cuttings from the bottom of the well hole. Some drill bits include nozzles that direct drilling fluid on the cutting elements to prevent clogging and balling up of the cutting elements in earth formations such as shale.
Many drill bits in current operation utilize rolling cutter cones mounted on the bit with sealed journal or roller bearings. During drilling operations, it is possible for drilling fines and shale packings to enter the bearing seal glands, thereby causing abrasion which lessens the life of the seals. If the seals are destroyed, the abrasive material can cause failure of the bearings. In any event, the life of the cutter cones can be significantly reduced due to failure of the bearings or the bearing seals. Although drilling fluid nozzles have been designed for cleaning and cooling the cutting elements, there are no nozzles presently available for directing fluid toward the bearing seals to prevent the buildup of cutting fines and shale packings around the bearing seals at the backface of the cutter cones. Thus, there is a need for an improved drilling fluid nozzle that directs some fluid toward the backface of the cutter cone to prevent abrasive formation cuttings from damaging the cutter cone bearings and seals.